Rectangular copper wire, also known as flat copper wire or rectangular magnet wire, plays a critical role in motors, transformers, and high-efficiency electrical equipment. Its space-saving shape allows more copper to fit into winding slots compared to round wire, improving electrical conductivity, reducing resistance, and enhancing thermal performance. In this article, we’ll explain how rectangular copper wire is produced and why precision manufacturing is essential for top performance.

Manufacturer of Rectangular Copper Wire Production Lines

Sky Bluer Environmental Technology Co., Ltd, based in China, is a leading manufacturer of rectangular copper wire production lines. We provide a complete range of machinery and parts, including payoff machines, wire drawing machines, wire rolling machines, annealing machines, wire take-up machines, and more.

We are a factory-direct machinery supplier offering competitive prices and strong production capacity, with the ability to produce up to 20 sets per month. If you require copper or brass wire machinery, please feel free to contact us. Our sales team provides one-on-one service, and if your order meets or exceeds our MOQ, we guarantee you will be fully satisfied.

1. Selecting High-Purity Copper

The production process begins with high-purity copper rods, most commonly electrolytic tough pitch (ETP) copper with conductivity close to 100% IACS, or oxygen-free copper (OFC) with even higher purity. These materials deliver excellent electrical conductivity, superior thermal stability, and strong mechanical performance, minimizing energy loss and ensuring long-term reliability. Their balance of ductility and tensile strength makes them especially well-suited for manufacturing rectangular copper magnet wire for motors, transformers, and other high-efficiency electrical applications.

2. Drawing the Copper into Round Wire

In the second stage of the process, the copper rod passes through a series of wire drawing dies to gradually reduce its diameter and achieve the desired tensile strength and elongation. At this point, the wire remains round in shape but is precisely prepared for the subsequent transformation into flat or rectangular profiles.

3. Rolling into a Rectangular Shape

In the third stage, a CRM 2025 copper wire rolling mill is used to pass the round wire through multiple rolling stands, gradually compressing it into a precise rectangular cross-section. This advanced rolling process guarantees consistent dimensions and a smooth surface finish, ensuring high-quality output for the next processing steps.

4. Heat Treatment and Stress Relief

In rectangular copper wire production, heat treatment—or annealing—is a crucial step that restores ductility and enhances the wire’s mechanical and electrical properties after drawing and rolling. The wire passes through a continuous annealing furnace, typically heated by electricity or gas, with temperatures carefully controlled between 350°C and 600°C depending on the copper grade and wire size. Protective gases, such as nitrogen or a hydrogen mix, prevent oxidation and maintain a bright surface finish. After heating, the wire is cooled—often by water or gas quenching—to stabilize its properties. This process produces a softer, more workable wire with consistent tensile strength and elongation, and a smooth, oxidation-free surface ideal for winding, enameling, or further shaping. At this stage, you can use your existing annealing machine, or we can supply a suitable annealing machine for your production line.

5. Surface Cleaning and Preparation

Before insulation, the wire is cleaned to remove oxides and processing residues. This improves adhesion for enamel coatings and ensures long-term reliability in demanding environments.

6. Applying Insulation or Enamel

For rectangular magnet wire manufacturing, an insulating enamel layer is applied to prevent short circuits between windings. Advanced coating methods provide high thermal resistance, making the wire suitable for motors, generators, and transformers.

7. Quality Control and Testing

Each batch of flat copper wire undergoes rigorous testing for dimensional accuracy, electrical conductivity, and insulation resistance. Strict quality control ensures that every product meets international standards and delivers reliable performance in industrial and automotive applications.

8. Delivery:20-30 working days

Final Thoughts

As a Chinese supplier, we have exported our products to more than 20 countries and hosted hundreds of customers to visit our factory. We provide online installation training, technical support, new machine design, and project estimation. We have a strict quality control system and at all times we believe that reputation and quality come first.

Producing high-quality rectangular copper wire requires a combination of advanced copper wire rolling mill technology, skilled engineering, and rigorous testing. At Sky Bluer Environmental Technology Co., Ltd China, we provide turnkey solutions for rectangular magnet wire production lines and supply high-precision equipment to customers worldwide.

If you’re looking for an experienced partner in flat copper wire manufacturing machines, contact us today to learn more about our technology and expertise.